Formation of coal and petroleum

The idea

Coal formed from remains of ancient plants pressed under layers of earth and rock; oil and gas formed from remains of tiny sea plants and animals buried under silt, which bacteria turned into oil and gas under high pressure.

Fuels from the past

Coal and petroleum are fuels we take from the earth. They are the remains of living things from millions of years ago.

What kind of living things formed coal?

• Trees, ferns and other plants
• Fish and other large animals
• Bacteria

Two long stories

Press Next step through the story of coal, then the story of oil and gas.

Plants and sea life, pressure and time

Both fuels come from the remains of living things that were buried and pressed for a very long time.

Coal formed from the remains of ancient plants pressed under layers of earth and rock. Oil and gas formed from the remains of tiny sea plants and animals buried under silt, which bacteria turned into oil and gas under high pressure.

Notes

Coal formed from remains of ancient plants pressed under layers of earth and rock; oil and gas from remains of tiny sea plants and animals buried under silt, which bacteria turned into oil and gas under high pressure.

Check yourself

Coal is the remains of which living things?

Oil and gas are the remains of which living things?

What did bacteria do in the formation of oil and gas?

What pressed the plants down when coal formed?

• Tiny plants and animals of the sea. Those formed oil and gas.
• Trees, ferns and other plants that lived millions of years ago — correct. Yes!
• Bacteria that lived in the silt. Bacteria acted on the dead remains of sea plants and animals to form oil and gas. Coal is the remains of plants.
• Trees and ferns. The remains of trees, ferns and other plants formed coal.
• Rocks and silt. Silt was compressed into rock. Oil and gas formed from the remains of tiny sea plants and animals.
• Millions of tiny plants and animals that lived in the sea — correct. Yes!
• Turned the dead remains into oil and gas under high pressure — correct. Yes!
• Compressed the silt into rock. The silt was slowly compressed into rock. Bacteria attacked the dead remains.
• Crushed the plants into the earth. Plants were crushed into the earth, perhaps by earthquakes or volcanic eruptions, in the story of coal.
• Layers of silt on the sea bed. Silt covered the dead sea plants and animals, which formed oil and gas. Plants for coal were pressed down by layers of earth and rock.
• Layers of earth and rock — correct. Yes!
• Bacteria. Bacteria acted on the sea remains that formed oil and gas. Coal plants were pressed down by layers of earth and rock.